A magnetic memory cell stores information by changing electrical resistance of a magnetic tunnel junction (MTJ) element. The MTJ element typically includes a fixed (pinned) magnetic layer and a free magnetic layer. The fixed (pinned) magnetic layer and the free magnetic layer are laminated such that a tunnel barrier film is formed between the two layers. Magnetic orientation of the free layer flips by a direction or an opposite direction of electric currents exceeding a critical select current. The electrical resistance of the MTJ element changes corresponding to that of the magnetic orientation of the free layer relating to the fixed (pinned) magnetic layer, which may be in either a parallel state or an anti-parallel state.
Magnetic memory cells require high write current to improve write speed for programming. However, high write current also results in a higher read current. High read current increases read disturb. For example, if the read current exceeds the critical switching current of MTJ (IC0), the read current could cause the free layer to switch directions, resulting in a read error.
From the foregoing discussion, it is desirable to provide magnetic memory cells with high write speed and read stability.